Heat exchanger

ABSTRACT

A heat exchanger includes a plate member having several continuously folded plates defining a first opening for reception of a fluid from a first direction and a second opening for reception of another fluid from a second direction, and a frame body enclosing the plate member. The frame body has bottom and top plates, left and right plates, and front and rear plates. Each left and right plate has a height smaller than a width of the folded plate member so that the left and right plate define an upper left hole and a lower left hole in cooperation with the top and bottom plates, and that the right plate defines an upper right hole and a lower right hole in cooperation with the top and bottom plates. Two gasket sheets are disposed on inner surfaces of the top and bottom plates in order to abut hermetically against top and bottom edges of the continuously folded plates.

FIELD OF THE INVENTION

The present invention relates to a heat exchanger, more particularly aplate-type heat exchanger including a folded plate member which servesas heat exchanging medium and which is composed of a plurality ofcontinuously folded plates that can be manufactured at a relatively lowcost and its maintenance is easy to conduct, thereby avoiding theproblems encountered during use of conventional plate/frame-type heatexchanger.

BACKGROUND OF THE INVENTION

Heat exchangers and its applications are well known in the art. The heatexchanging principle is very easy to understand, i.e. in case first andsecond fluids are disposed within a receptacle, the fluids tend toexchange heat between each other. Though, the heat exchanging principleis simple, its applications reaches various fields. For instance, theheat exchanging is widely utilized in nuclear power plants, petroleumprocessing plant, chemical plant, paper production mill, airconditioner, seawater desalination plant, and many others. Heatexchangers are applied in heating, cooling, vaporizing, condensing,energy recycling plant and so forth.

Fundamentally, there are two main types of heat exchangers, namely: (1)tube/shell-type heat exchanger and (2) plate/frame-type heat exchanger.FIG. 1A shows a conventional tube/shell-type heat exchanger 90 andincludes a shell body 120 enclosing an upper plate 100 formed with aplurality of coupling holes, a lower plate 110 formed with a pluralityof coupling holes, and a plurality small tubes 105 extending into thecoupling holes in the upper and lower plates 100,110. The shell body 120has an upper inlet (102I) formed between the upper plate 100 and theleft side wall of the body 120 and via which a first fluid is injectedinto a first space defined between the upper plate 100 and the left sidewall of the body 120, and a lower outlet (102O) formed between the rightside wall of the shell body 120 and the lower plate 110 and via whichthe first fluid flows out. The shell body 120 further has a lower inlet(106I) formed between the upper and lower plates 100, 110 via which asecond fluid is injected, and an upper outlet (106O) formed between theupper and lower plates 100, 110 via which the second fluid flows outfrom the shell body 120.

In the aforesaid heat exchanger 90, the surfaces of the small tubes 105enable the majority of the heat exchanging operation between the firstand second fluids.

Note that in the aforesaid heat exchanger 90, the small tubes 105 arelocated too densely such that it is relatively complicated, high cost,and difficult to weld the small tubes 105 so as to be integrally fromwith the peripheries confining the coupling holes in the upper and lowerplates 100, 110. In the event, a great number of gasket rings or sheetsare utilized instead of the welding process, a considerable manual laborand cost is still required for hermetically sealing the peripheriesconfining the mounting holes in the upper and lower plates 100, 110.Some stuffing substance, such as resin, can be squeezed into theclearances formed among the small tubes 150 and the peripheries of themounting holes in the upper and lower plates 100, 110 in order toprovide leak-proof effect. In case, the periphery weld or sealing of thecoupling hole in the upper or lower plate is leaking or damaged, agingof the gasket rings or sheets due to long term use, it is not easy orpossible to trouble shoot the problems. It is also relatively difficultto clean the space located between the small tubes 105.

FIG. 1B illustrates a conventional plate/frame-type heat exchanger 150,which includes a plurality of flat exchange plates 155 and a frame body(not shown). Each heat exchange plate 155 is formed with two upper holes156A, 156B at an upper section and two lower holes 157A, 157B at a lowersection. Several gaskets, in the form of a ring, are provided around theholes in the heat exchange plate 155 in order to provide the leak-proofeffect. In the same manner, several gasket sheets 160 are provided atthe outer periphery of the heat exchange plate 155 in order to providethe leak-proof effect. Since each gasket has a predetermined thickness,after assembly by pressing, housing space 161, 162, 163 is definedbetween adjacent two of the heat exchange plates 155.

Though no welding process is required when manufacturing the aforesaidconventional plate/frame-type heat exchanger 150, the manufacture costis still high because the gaskets 160 are laid adhesively and manuallyone after another. After assembly and after a period of time, in case ofleaking or aging of the gaskets, it is relatively difficult and possibleto conduct the essential maintenance of the aforesaid heat exchanger,since all the gaskets 160 are located in the inner portion.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a heat exchanger thatcan be manufactured at a low cost and that can be maintained with ease.

In accordance with the present invention, the first embodiment of a heatexchanger is provided and includes a folded plate member with apredetermined length and width, a frame body and two gasket sheets. Thefolded plate member includes a plurality of continuously folded platesdefining a first opening for reception of a first fluid from a firstdirection and a second opening for reception of a second fluid from asecond direction opposite to the first direction. The frame bodyencloses the folded plate member therein, and includes a bottom plate, atop plate, left and right plates, and front and rear plates, whereineach of the left and right plates has a height smaller than the width ofthe folded plate member so that the left plate defines an upper lefthole and a lower left hole in cooperation with the top and bottomplates, and that the right plate defines an upper right hole and a lowerright hole in cooperation with the top and bottom plates. The gasketsheets are disposed on inner surfaces of the top and bottom plates inorder to abut hermetically against top and bottom edges of thecontinuously folded plates. In addition, a spacer is disposed between anadjacent pair of the continuously folded plates in order to preventionvariation of a clearance defined between two adjacent folded plates dueto pressure difference between the first and second fluids.

In accordance with the present invention, the second embodiment of theheat exchanger is provided to have the structure similar to the firstembodiment. The only difference resides in that the continuously foldedplates have a plain surface including a predetermined regionsrespectively aligned with the upper and lower left holes in the leftplate, and the upper and lower right holes in the right plate, andremaining regions which are offset to the holes in the left and rightplates and are dented or pressed with a predetermined pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same becomesbetter understood by reference to the following detailed description,when taken in conjunction with the accompanying drawings, wherein:

FIG. 1A shows a schematic view of a conventional tube/shell-type heatexchanger;

FIG. 1B shows an exploded view of a conventional plate/frame-type heatexchanger;

FIG. 2A is a top view of the first embodiment of a heat exchanger of thepresent invention with the top plate removed in order to illustrate aninterior thereof;

FIG. 2B is a cross-section view of the first embodiment of the heatexchanger of the present invention taken along line P-P′ in FIG. 2Ashown together with top and bottom plates;

FIG. 2C is across-section view of the first embodiment of the heatexchanger of the present invention taken along line Q-Q′ in FIG. 2Ashown together with top and bottom plates;

FIG. 2D is a cross-section view of the first embodiment of the heatexchanger of the present invention with the top plate removed in orderto illustrate an interior thereof;

FIG. 3A illustrates a stretch-out view of an elongated flat plate priorto forming the folded plate member of the second embodiment of the heatexchanger of the present invention; and

FIG. 3B is a cross-section view of the continuously folded platescooperatively forming the folded plate member employed in the secondembodiment of the heat exchanger of the present invention;

FIG. 3C illustrates an another stretch-out view of an elongated flatplate prior to forming the folded plate member of the second embodimentof the heat exchanger of the present invention; and

FIG. 3D is a cross-section view of the continuously folded platescooperatively forming the folded plate member employed in the secondembodiment of the heat exchanger of the present invention.

FIGS. 4A to 4C are top view of the heat exchanger without the top plateaccording to the present invention.

FIG. 4D is a cross-section view taken along line P-P′ in FIG. 4A showntogether with top and bottom plates according to the present invention.

FIG. 4E is a cross-section view taken along line Q-Q′ in FIG. 4A showntogether with top and bottom plates according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The heat exchanger provided according to the present invention can bemanufactured at a relatively low cost in addition to easy maintenancethereof.

FIG. 2A illustrates a top view of the first embodiment of a heatexchanger of the present invention with the top plate removed in orderto illustrate an interior thereof. The heat exchanger includes a heatexchanging folded plate member 5 with a predetermined length and width,a frame body and two gasket sheets 15. The plate member 5 in fact is anelongated metal or heat conductive plate having a thickness betweenabout 0.1 mm to 2 mm, a width W between about 30 cm to 5 meter, and arelatively longitudinal length according to the required folded numbers.The aforesaid elongated metal plate is bent continuously utilizingmechanical processes so as to obtain a plurality of continuously foldedplates 5M and a plurality of joint portions 5L, 5R, each of whichinterconnects two adjacent folded plates 5M. The frame body includes abottom plate 8B, a top plate 8A, left and right plates 6A, 6B, and frontand rear plates 7A, 7B which cooperatively encloses the continuouslyfolded plates 5M in such a manner that the latter define a plurality offirst openings OL for reception of a first fluid from a first directionand a plurality of second openings OR for reception of a second fluidfrom a second direction opposite to the first direction. Note that twoadjacent folded plates 5M are spaced apart from each other by a gapranging from 2 mm to 20 mm.

FIG. 2B is a cross-section view of the first embodiment of the heatexchanger of the present invention taken along line P-P′ in FIG. 2Ashown together with the top and bottom plates 8A, 8B. FIG. 2C is across-section view of the first embodiment of the heat exchanger of thepresent invention taken along line Q-Q′ in FIG. 2A shown together withtop and bottom plates 8A, 8B. As illustrated, each of the left and rightplates 6A, 6B has a height (H) smaller than the width W of the foldedplate member 5 so that the left plate 6A defines an upper left hole 12ULand a lower left hole 12DL in cooperation with the top and bottomplates, and that the right plate 6B defines an upper right hole 12UR anda lower right hole 12DR in cooperation with the top and bottom plates8A, 8B. Note that the upper right hole 12UR and a lower right hole 12DRin the right plate 6B are shielded by the joint portions 5Rinterconnecting the folded plates 5M (see FIG. 2B). In the same mannerthe upper left hole 12UL and a lower left hole 12DL in the left plate 6Aare shielded by the joint portions 5L interconnecting the folded plates5M (see FIG. 2C).

Note that each of the upper left and right holes 12UL, 12UR has a height(Hu) greater than the height (Hd) defined by the lower left and rightholes 12DL, 12DR. The purpose of designing the height (Hu) of the upperleft and right holes 12UL, 12UR greater than the height (Hd) defined bythe lower left and right holes 12DL, 12DR is to facilitate smooth flowof the first and second fluids. For instance, the upper left and rightholes 12UL, 12UR in the left and right plates 6A, 6B permit smoothoutflow of a vapor-type fluid while the lower left and right holes 12DL,12DR in the left and right plates 6A, 6B permits smooth outflow of acondensate fluid. Of course, the vapor fluid and the condensate orliquid fluid may have different volume. In case, the aforesaid first andsecond fluids are both liquid or vapor (gas), the height (Hu) of theupper left and right holes 12UL, 12UR and the height (Hd) of the lowerleft and right holes 12DL, 12DR can be designed to have the samemeasurement.

The shape of each of the joint portions 5L, 5R should not be flat, butis rather curved. The curvature of the surface of each joint portion 5L,5R should not be limited. Preferably, the joint portions 5L, 5R (or leftand right edges) of the continuously folded plates 5M are in contactwith the inner surface of the left and right plates 6A, 6B.

The gasket sheets 15 are disposed on inner surfaces of the top andbottom plates 8A,8B in order to abut hermetically against top and bottomedges of the continuously folded plates 5M in such a manner that the topand bottom edges of the continuously folded plates 5M extend partiallyinto the gasket sheets 15. Each of the gasket sheets 15 has a thicknessbetween about 10 mm to 100 mm, and is made from an elastomeric material.The elastomeric material is selected from a material group includingrubber and silica gel.

FIG. 2D is a cross-section view of the first embodiment of the heatexchanger of the present invention with the top plate removed in orderto illustrate an interior thereof. As illustrated, the first embodimentfurther includes a spacer 20L, 20R disposed between an adjacent pair ofthe continuously folded plates 5 M in order to prevention variation of aclearance “d” defined between the adjacent folded plate 5M due topressure difference between the first and second fluids. The spacer 20L,20R includes a plurality of long and short strips 20A, 20B connected toone another in criss-cross manner. Preferably, the spacer 20L, 20R has aweb-like configuration. Each long strip 20A is connected transversely toseveral short strips 20B, and has one end connected to the plates 6A,6B, as shown in FIG. 2D, or not (not shown).

During the assembly, each spacer 20L is inserted into the respectivefirst openings OL of the continuously folded plates 5M. In the samemanner, each spacer 20R is inserted into the respective second openingsOR of the continuously folded plates 5M. In other words, the long strip20A between two adjacent folded plates 5M has one end connected to theleft and right plates 6A, 6B, respectively. Alternately, the spacers 20Land 20R are just disposed into the openings OL and OR without connectedto the left plate 6A and the right plate 6B. Optionally, to make uniformdistribution of the injected fluid, the cross-section of each of thelong strip 20A is gradually tapered to the free end with respect to thefixed end. The front plate 7A is mounted to the front ends of the leftand right plates 6A, 6B. Afterward, the rear plate 7B is mounted to therear ends of the left and right plate 6A, 6B so as to define a casinghaving bottom and top openings. The material for forming the long andshort strips 20A, 20B can be selected from a metal group and non-metalmaterials, or a combination of any one of the metals and the non-metalmaterials.

After the aforementioned process, one gasket sheet 15 is disposed on theinner surface of the bottom plate 8B. The lower edges of thecontinuously folded plates 5M are pressed into the gasket sheet 15 onthe bottom plate 8B. The other gasket sheet 15 is disposed on the innersurface of the top plate 8A prior to pressing the gasket sheet 15 ontothe top edges of the continuously folded plates 5M.

In the first embodiment, the second fluid with a higher temperature canbe injected from the upper right opening 12UR in the right plate 6B (seeFIG. 2C) while the first fluid with a lower temperature can be injectedfrom the lower left opening 12DL in the left plate 6A (see FIG. 2B) suchthat after the heat exchanging operation, the fluids will flow out viathe lower right openings 12DR in the right plate 6B. In the same manner,the first fluid with a lower temperature can be injected from the lowerleft opening 12DL in the left plate 6A such that after the heatexchanging operation, the first fluid has a temperature higher than itsinitial ones and flows out via the upper left hole 12UL in the leftplate 6A. Note that the first and second fluids can be injected into theframe body from along one diagonal direction of the frame body and thesame flow out along another diagonal direction of the frame body afterthe heat exchange operation.

The aforesaid first fluid should not be restricted to any specific type.The second fluid should not be restricted either, i.e. liquid or gas orvapor.

FIG. 3A illustrates a stretch-out view of an elongated plate prior toforming the folded plate member of the second embodiment of the heatexchanger of the present invention. The second embodiment has thestructure similar to the first embodiment, except in that thecontinuously folded plates 5M have a surface area including apredetermined regions respectively aligned with the upper and lower leftholes 12UL, 12DL in the left plate 6A, and the upper and lower rightholes 12UR, 12DR in the right plate 6B, and a remaining regions whichare pressed or dented to form a predetermined pattern 40. Note that forforming the predetermined pattern 40, a steel roller (not shown) withsmooth surface is first rolled over (dry rolling process) the surface ofthe elongated metal plate so as to provide an even surface and the evensurface is later again rolled over by another steel roller (not shown)having a plurality parallel ribs of specific pattern such that theremaining regions of the continuously folded plates 5M are dented withthe predetermined pattern 40. Alternatively, pressing actions can beconducted onto the remaining regions of the continuously folded plates5M in order to form the predetermined pattern 40.

The configuration of the predetermined pattern 40 should not be limitedto any particular design, but is to encompass various designs.

FIG. 3B is a cross-section view of the continuously folded plates thatcooperatively form the folded plate member 5 employed in the secondembodiment of the heat exchanger of the present invention. Thepredetermined pattern 40 is preferably composed of a plurality ofparallel trenches 41, each of which extends in a direction transverseinclinedly to the longitudinal length of the folded plate member 5, asbest shown in FIG. 3A. Alternatively, each trench 41 may extend in adirection transverse perpendicularly to the longitudinal length of thefolded plate member 5, as best shown in FIG. 3C.

In the aforesaid embodiment, due to formation of the trenches 41, eachof the folded plates 5M has a plurality of concave portions and aplurality of convex portions respectively between two adjacent concaveportions. Under this condition, in case two adjacent folded plates 5Mare folded, as best illustrated in FIG. 3B, in such a manner to abutagainst each other, the convex portions of the two adjacent foldedplates 5M contact one another while the concave portions thereofcooperatively define a plurality of channels to confine injected fluidsflowing along the channels. Note that formation of the trenches 41(hence the concave portion and convex portions) in the folded plates 5Mincreases the surface area for contacting with the fluids and increasesthe heat transfer rate and also increases the uniform distribution ofthe fluids. Due to the aforementioned facts, the heat transfer abilityof the heat exchanger of the present invention is tremendously enhanced.

FIG. 3D is another cross-section view of the continuously folded platescooperatively forming the folded plate member employed in the secondembodiment of the heat exchanger of the present invention shown in FIG.3C. The only difference resides in that the concave and convex portionsof the adjacent two folded plates 5M do not contact each other but withone spacer 15 in each adjacent pair of continuously folded plates toform channels.

Referring to FIGS. 3A and 3C again, the continuously folded plates 5Mfurther have a transition region (shown by x-x′/y-y′ lines) between thepredetermined region and the remaining region. The surface area in thetransition region of the folded plates 5M should preferably be formedwith an inclined slope that gradually inclines from the predeterminedregion to the remaining region.

According to another preferred embodiment of the present invention, theheat exchanger is composed of the continuously folded plates 5M, twogasket sheets 15, a top plate 8A, a bottom plate 8B, a front plate 7Aand a rear plate 7B, as is shown in FIGS. 4A to 4E. The first one of thegasket sheets 15 is disposed between the top plate 8A and the upperedges of the continuously folded plates 5M, and the second one 15 isdisposed between the bottom plate 8B and the bottom edges of thecontinuously folded plates 5M as aforementioned.

FIGS. 4A to 4C are top view of the heat exchanger without the top plate8A. FIG. 4A shows the continuously folded plates are formed of plainsurfaces and openings OL, OR inserted with spacers. FIG. 4B shows thecontinuously folded plates without spacers. The continuously foldedplates have concave and convex pattern formed in such a manner that theconvex portions of the two adjacent plates 5M are contact while theconcave portions thereof cooperatively define a plurality of channels.FIG. 4C shows the continuously folded plates with concave and convexpattern and spacers. Each spacer is disposed into each adjacent pair ofthe continuously folded plates 5M.

FIG. 4D is a cross-section view taken along line P-P′ in FIG. 4A showntogether with top and bottom plates.

FIG. 4E is a cross-section view taken along line Q-Q′ in FIG. 4A showntogether with top and bottom plates.

The operations of the heat exchanger are implemented by flowing in andout through the first openings OL with a first fluid and through thesecond openings OR with a second fluid.

The following advantages are achieved when the heat exchanger of thepresent invention is utilized.

(i) When compared to the conventional tube/shell-type heat exchanger, nowelding process is required for sealing and connecting the tubes to thetop and bottom plates, thereby tremendously lowering the manufacturingand maintenance expense.

(ii) When compared to the conventional plate/frame-type heat exchanger,the gasket sheets are only provided at the top and bottom plates of theshell body. Under this condition, in case the gasket sheets are damageddue to long-term use, fatigue or leakage, replacement thereof can beconducted by simply removing the top and bottom plates with respect tothe frame body. Therefore, the maintenance fee is tremendously low. Incontrast, since all the gasket sheets or rings are mounted interior ofthe conventional plate/frame heat exchanger, it is not easy or possibleto check and maintenance the condition of the plate/frame heatexchanger. In addition,

The heat exchanger of the present invention is cleared from thedisadvantages the aforementioned items (I) and (II). This invention cantremendously reduce the manufacturing and maintenance expense andproblem.

As is understood by a person skilled in the art, the foregoing preferredembodiment of the present invention is an illustration of the presentinvention rather than limiting thereon. It is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims, the scope of which should be accorded thebroadest interpretation so as to encompass all such modifications andsimilar structure.

1. A heat exchanger comprising: a folded plate member with apredetermined length and width, including a plurality of continuouslyfolded plates defining a first opening for reception of a first fluidfrom a first direction and a second opening for reception of a secondfluid from a second direction opposite to said first direction; a framebody enclosing said folded plate member therein, and including a bottomplate, a top plate, and left and right plates, wherein each of said leftand right plates has a height smaller than said width of said foldedplate member so that said left plate defines an upper left hole and alower left hole in cooperation with said top and bottom plates, and thatsaid right plate defines an upper right hole and a lower right hole incooperation with said top and bottom plates; and two gasket sheetsdisposed on inner surfaces of said top and bottom plates in order toabut hermetically against top and bottom edges of said continuouslyfolded plates.
 2. The heat exchanger according to claim 1, wherein saidframe body further includes front and rear plates connected to saidbottom plate, said top plate, and said left and right plates.
 3. Theheat exchanger according to claim 1, wherein said folded plate member ismade from a heat conductive material, and has a thickness between about0.1 mm to 2 mm.
 4. The heat exchanger according to claim 3, wherein saidheat conductive material is selected from a metal group including steel,brass, zinc, chromium, aluminum, alloy and titanium.
 5. The heatexchanger according to claim 1, wherein each of said gasket sheets ismade from an elastomeric material.
 6. The heat exchanger according toclaim 5, wherein each of said elastomeric material is selected from amaterial group including rubber and silica gel.
 7. The heat exchangeraccording to claim 1, wherein inner surfaces of said left and rightplates are in contact with left and right edges of said continuouslyfolded plates.
 8. The heat exchanger according to claim 1, wherein eachof said continuously folded plates has a flat surface.
 9. The heatexchanger according to claim 1, further comprising a plurality ofspacers, each disposed between an adjacent pair of said continuouslyfolded plates in order to prevention variation of a clearance definedbetween said adjacent pair of folded plates due to pressure differencebetween said first and second fluids.
 10. The heat exchanger accordingto claim 9, wherein said spacer includes long and short strips connectedto each other.
 11. The heat exchanger according to claim 9, wherein saidspacer has a web-like configuration.
 12. The heat exchanger according toclaim 1, wherein said continuously folded plates have a surface areaincluding a predetermined regions respectively aligned with said upperand lower left holes in said left plate and said upper and lower rightholes in said right plate, and a remaining regions which are pressed ordented with a predetermined pattern.
 13. The heat exchanger according toclaim 12, wherein said predetermined pattern is composed of a pluralityof trenches and wherein each of said continuously folded plates has aplurality of concave portions and a plurality of convex portionsrespectively between two adjacent concave portions due to formation ofsaid trenches.
 14. A heat exchanger comprising: a folded plate memberwith a width, including a plurality of continuously folded platesdefining a first opening for reception of a first fluid from a firstdirection and a second opening for reception of a second fluid from asecond direction opposite to said first direction; a frame bodyenclosing said folded plate member therein, and including a bottomplate, a top plate, a rear plate, a front plate, a left plate and aright plate, said left and right plates in tight abutment with left andright edges of said folded plates, respectively, wherein each of saidleft and right plates has a height smaller than said width of saidfolded plate member so that said left plate defines an upper left holeand a lower left hole in cooperation with said top and bottom plates,and that said right plate defines an upper right hole and a lower righthole in cooperation with said top and bottom plates; a plurality ofspacers, each disposed between an adjacent pair of said continuouslyfolded plates in order to prevention variation of a clearance definedbetween said adjacent pair folded plates due to pressure differencebetween said first and second fluids; and two gasket sheets disposed oninner surfaces of said top and bottom plates in order to abuthermetically against top and bottom edges of said continuously foldedplates.
 15. A heat exchanger comprising: a folded plate member with awidth, including a plurality of continuously folded plates defining afirst opening for reception of a first fluid from a first direction anda second opening for reception of a second fluid from a second directionopposite to said first direction; a frame body enclosing said foldedplate member therein, and including a bottom plate, a top plate, andleft and right plates, wherein each of said left and right plates has aheight smaller than said width of said folded plate member so that saidleft plate defines an upper left hole and a lower left hole incooperation with said top and bottom plates, and that said right platedefines an upper right hole and a lower right hole in cooperation withsaid top and bottom plates, wherein, said continuously folded platescooperatively have a surface area including a predetermined regionsrespectively aligned with said upper and lower left holes in said leftplate, and said upper and lower right holes in said right plate, andremaining regions which are pressed or dented in such a manner to form apredetermined pattern; and two gasket sheets disposed on inner surfacesof said top and bottom plates in order to abut hermetically against topand bottom edges of said continuously folded plates.
 16. The heatexchanger according to claim 15, wherein said frame body furtherincludes front and rear plates connected to said bottom plate, said topplate, and said left and right plates.
 17. A heat exchanger comprising:a folded plate member formed of a plurality of continuously foldedplates defining a first opening for reception of a first fluid from afirst direction and a second opening for reception of a second fluidfrom a second direction opposite to said first direction; a frame bodyincluding a bottom plate, a top plate, a front plate and a rear plate;and two gasket sheets disposed on inner surfaces of said top and bottomplates in order to abut hermetically against top and bottom edges ofsaid continuously folded plates.
 18. The heat exchanger according toclaim 17, further comprising a plurality of spacers, each disposedbetween an adjacent pair of said continuously folded plates.
 19. Theheat exchanger according to claim 17, wherein said continuously foldedplates have a concave and convex pattern formed in such a manner thatthe convex portions of the two adjacent plates are contact while theconcave portions thereof cooperatively define a plurality of channels.20. The heat exchanger according to claim 17, wherein said continuouslyfolded plates have a concave and convex pattern formed and with onespacer disposed in each adjacent pair of said continuously foldedplates.